The costs of carnivory
The costs of carnivory
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DOI：
10.1371/journal.pbio.0050022
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发表时间：
2007-02-01
期刊：
影响因子：
9.8
通讯作者：
Rowcliffe, J. Marcus
中科院分区：
文献类型：
--
作者：
Carbone, Chris;Teacher, Amber;Rowcliffe, J. Marcus
哺乳动物食肉动物可分为两大类：小型食肉动物（体重约20公斤），以非常小的猎物（无脊椎动物和小型脊椎动物）为食；大型食肉动物（体重约20公斤）。20公斤)，专门以大型脊椎动物为食。我们开发了一个模型来预测这些群体中与质量相关的能量预算和食肉动物大小的限制。我们发现猎物从小到大的转变可以通过净能量增益最大化来预测；大型食肉动物通过专注于大型猎物来获得更高的净增益率。然而，因为它需要更多的能量来追捕和制服大型猎物，这导致能量消耗增加了两倍，同时摄入也增加了。在所有物种中，能量消耗和摄入都与体重成四分之三的比例。然而，当每个饮食组单独考虑时，它们都显示出较浅的缩放。这表明，每一组食肉动物的上限都受到摄入量的限制，并采取节约能量的策略来应对这种情况。根据对消耗和摄入的预测，我们预测食肉动物的最大体重约为一吨，与最大的灭绝物种一致。我们的方法为理解食肉动物的能量学、大小和灭绝动力学提供了一个框架。
Mammalian carnivores fall into two broad dietary groups: smaller carnivores (, 20 kg) that feed on very small prey ( invertebrates and small vertebrates) and larger carnivores (. 20 kg) that specialize in feeding on large vertebrates. We develop a model that predicts the mass-related energy budgets and limits of carnivore size within these groups. We show that the transition from small to large prey can be predicted by the maximization of net energy gain; larger carnivores achieve a higher net gain rate by concentrating on large prey. However, because it requires more energy to pursue and subdue large prey, this leads to a 2-fold step increase in energy expenditure, as well as increased intake. Across all species, energy expenditure and intake both follow a three-fourths scaling with body mass. However, when each dietary group is considered individually they both display a shallower scaling. This suggests that carnivores at the upper limits of each group are constrained by intake and adopt energy conserving strategies to counter this. Given predictions of expenditure and estimates of intake, we predict a maximum carnivore mass of approximately a ton, consistent with the largest extinct species. Our approach provides a framework for understanding carnivore energetics, size, and extinction dynamics.